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AIM

10/12/17

7−4−1

Bird Hazards and Flight Over National Refuges, Parks, and Forests

Section 4. Bird Hazards and Flight Over National

Refuges, Parks, and Forests

7−4−1. Migratory Bird Activity

a. Bird strike risk increases because of bird

migration during the months of March through April,

and August through November.

b. The altitudes of migrating birds vary with winds

aloft, weather fronts, terrain elevations, cloud

conditions, and other environmental variables. While

over 90 percent of the reported bird strikes occur at or

below 3,000 feet AGL, strikes at higher altitudes are

common during migration. Ducks and geese are

frequently observed up to 7,000 feet AGL and pilots

are cautioned to minimize en route flying at lower

altitudes during migration.

c. Considered the greatest potential hazard to

aircraft because of their size, abundance, or habit of

flying in dense flocks are gulls, waterfowl, vultures,

hawks, owls, egrets, blackbirds, and starlings.

Four major migratory flyways exist in the U.S. The

Atlantic flyway parallels the Atlantic Coast. The

Mississippi Flyway stretches from Canada through

the Great Lakes and follows the Mississippi River.

The Central Flyway represents a broad area east of the

Rockies, stretching from Canada through Central

America. The Pacific Flyway follows the west coast

and overflies major parts of Washington, Oregon, and

California. There are also numerous smaller flyways

which cross these major north-south migratory

routes.

7−4−2. Reducing Bird Strike Risks

a. The most serious strikes are those involving

ingestion into an engine (turboprops and turbine jet

engines) or windshield strikes. These strikes can

result in emergency situations requiring prompt

action by the pilot.

b. Engine ingestions may result in sudden loss of

power or engine failure. Review engine out

procedures, especially when operating from airports

with known bird hazards or when operating near high

bird concentrations.

c. Windshield strikes have resulted in pilots

experiencing confusion, disorientation, loss of

communications, and aircraft control problems.

Pilots are encouraged to review their emergency

procedures before flying in these areas.

d. When encountering birds en route, climb to

avoid collision, because birds in flocks generally

distribute themselves downward, with lead birds

being at the highest altitude.

e. Avoid overflight of known areas of bird

concentration and flying at low altitudes during bird

migration. Charted wildlife refuges and other natural

areas contain unusually high local concentration of

birds which may create a hazard to aircraft.

7−4−3. Reporting Bird Strikes
Pilots are urged to report any bird or other wildlife

strike using FAA Form 5200−7, Bird/Other Wildlife

Strike Report (Appendix 1). Additional forms are

available at any FSS; at any FAA Regional Office or

at https://www.faa.gov/airports/airport_safety/

wildlife/. The data derived from these reports are used

to develop standards to cope with this potential

hazard to aircraft and for documentation of necessary

habitat control on airports.

7−4−4. Reporting Bird and Other Wildlife

Activities
If you observe birds or other animals on or near the

runway, request airport management to disperse the

wildlife before taking off. Also contact the nearest

FAA ARTCC, FSS, or tower (including non−Federal

towers) regarding large flocks of birds and report the:

a. Geographic location.
b. Bird type (geese, ducks, gulls, etc.).
c. Approximate numbers.
d. Altitude.
e. Direction of bird flight path.